Sacramento, Calif. — GEI Consultants, Inc. announced that its client, the San Diego County Water Authority, recently dedicated the San Vicente Dam Raise, the final major piece of the Water Authority's $1.5 billion Emergency Storage Project (ESP). The ESP consists of a system of reservoirs, interconnected pipelines, and pumping stations that will ensure the region has a six-month supply of water in the event of an interruption of imported water deliveries.
GEI has provided engineering services to the Water Authority on a continuous basis for the last 22 years to bring the ESP to fruition, encompassing all project phases – planning, design, construction, and operation. In addition to the San Vicente Dam Raise, the ESP has also included the following notable projects: Olivenhain Dam, the tallest roller compacted concrete (RCC) dam in North America; a pump station and tunneled pipeline to deliver Lake Hodges water to Olivenhain Reservoir, which also includes a pumped-storage component to generate hydroelectricity; and a pump station and 11-mile long large-diameter tunnel to connect San Vicente Reservoir with the regional aqueduct system. GEI assisted the Water Authority in obtaining environmental approvals for the ESP, and developed conceptual designs of all facilities, annual operation plans for storage reservoirs, emergency water delivery plans for allocating available supplies in an emergency event, and aqueduct operation plans for regional distribution of emergency water supplies.
The recently completed San Vicente Dam Raise expands the capacity of the reservoir by 152,000 acre-feet to over 242,000 acre-feet, which includes 100,000 acre-feet of carryover storage for use in times of drought. The original 220-foot-high concrete dam was raised 117 feet using RCC, making it the highest dam raise in the country and highest dam raise in the world using RCC.
GEI's scope of services for the dam raise included: planning studies to determine the optimal height of the raise; engineering analysis to support CEQA/NEPA documentation for the additional carryover storage component of reservoir expansion; seismicity analyses; a comprehensive geotechnical investigation program; inspection and analysis of the existing dam, hydrologic and hydraulic evaluations; conceptual designs for raising the dam and appurtenant structures; dynamic analyses of the composite concrete/RCC structure; dam breach inundation mapping; constructability analysis; cost estimating; and development of reservoir operations plans for construction and post-construction.
A critical element of the project was the conceptual design of a new outlet works system, involving construction in an active reservoir. GEI developed a cost effective concept for the new outlet works, involving a dual system consisting of an outlet works tower on one of the abutments and a separate low level outlet near the center of the dam. This concept reduced the amount of underwater construction, reduced costs, and reduced construction risks.
"GEI is proud to have played an integral role in the success of the Emergency Storage Project which is so vital to the San Diego region," said GEI President Raymond Hart.